Patellofemoral joint arthroplasty: patient selection,surgical technique and outcomes

Isolated patellofemoral arthritis is an increasingly recognized entity, and is usually associated with previous patellofemoral dysplasia or instability. Patellofemoral arthroplasty (PFA) has evolved significantly in recent years, both in terms of implant design and importantly in the understanding of appropriate patient selection. This review outlines the indications and investigations for PFA, provides a brief history of the development of contemporary implants, and presents the clinical outcomes for the prostheses most commonly used in the UK. In addition, it provides a detailed surgical technique for implantation of an onlay implant, with tips on how to optimize patellofemoral biomechanics and thus achieve a consistently good outcome.     

Treatment of refractoriness to platelet transfusion by protein A column therapy

Ten thrombocytopenic patients (platelets < 10–24 × 10(9)/L) who were refractory to platelet transfusion were investigated for their responsiveness to staphylococcal protein A column therapy. Nine patients had previously been treated with steroids, intravenous immune globulin, and/or other forms of immunosuppressive therapy without improvement in their transfusion response. All patients were receiving multiple platelet transfusions without achieving 1-hour corrected count increments (CCIs) > or = 7500. Eight patients had antibodies that reacted with platelets and were directed against HLA class I antigens, ABO antigens, and/or platelet-specific alloantigens. Plasma (500-2000 mL) from each patient was passed over a protein A silica gel column and then returned to the patient. Patients received from 1 to 14 treatments. A positive response to protein A therapy was defined as at least a doubling of the pretreatment platelet count and/or two successive 10- to 120-minute posttransfusion CCIs > or = 7500. Following plasma treatments, 6 of 10 patients responded with daily platelet counts that averaged 48 +/− 11 × 10(9) per L as compared with counts of 16 +/− 7 × 10(9) per L (p < 0.0005) before treatment. Posttransfusion CCI values determined in four of these patients averaged 2480 +/− 810 and 10,010 +/− 3540 (p < 0.005) before and after treatment, respectively. In contrast, among the four unresponsive patients, platelet counts averaged 10 +/− 9 and 13 +/− 10 × 10(9) per L (p = NS), respectively, while posttransfusion CCIs were 700 +/− 1410 and 1520 +/− 2460 (p = NS), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

乳酸脱氢酶实验检测细胞新陈代谢的实验研究

目的 探索LDH实验检测细胞活力的可行性。方法 原代培养骨髓细胞和软骨细胞，用LDH实验测定上述两组细胞的活力，并与镜下活体观察到细胞的生长状况相比较。与目前比较成熟的测定细胞活力的MTS实验的测得的值相比较。结果 LDH实验对上述两组细胞的活力的测定结果与镜下活体观察到的结果相符合。与MTS实验的测得的结果经统计学处理无显著差异。结论 LDH实验可用于细胞活力的直接测定，而对活细胞的生存、繁殖无影响。     

Prospective, randomized trial on the effect of cyclic versus continuous enteral nutrition on postoperative gastric function after pylorus-preserving pancreatoduodenectomy.

OBJECTIVE: The effect of a cyclic versus a continuous enteral feeding protocol on postoperative delayed gastric emptying, start of normal diet, and hospital stay was assessed in patients undergoing pylorus-preserving pancreatoduodenectomy (PPPD). SUMMARY BACKGROUND DATA: Delayed gastric emptying occurs in approximately 30% of patients after PPPD and causes prolonged hospital stay. Enteral nutrition through a catheter jejunostomy is used to provide postoperative nutritional support. Enteral infusion of fats and proteins activates neurohumoral feedback mechanisms and therefore can potentially impair gastric emptying and prolong postoperative gastroparesis. METHODS: From September 1995 to December 1996, 72 consecutive patients underwent PPPD at the Academic Medical Center, Amsterdam. Fifty-seven patients were included and randomized for either continuous (CON) jejunal nutrition (0-24 hr; 1500 kCal/24 hr) or cyclic (CYC) enteral nutrition (6-24 hr; 1125 kCal/18 hr). Both groups had an equal caloric load of 1 kCal/min. The following parameters were assessed: days of nasogastric intubation, days of enteral nutrition, days until normal diet was tolerated orally, and hospital stay. On postoperative day 10, plasma cholecystokinin (CCK) levels were measured during both feeding protocols. RESULTS: Nasogastric intubation was 9.1 days in the CON group (n = 30) and 6.7 days in the CYC group (n = 27) (not statistically significant). First day of normal diet was earlier for the CYC group (15.7 vs. 12.2 days, p < 0.05). Hospital stay was shorter in the CYC group (21.4 vs. 17.5 days, p < 0.05). CCK levels were lower in CYC patients, before and after feeding, compared with CON patients (p < 0.05). CONCLUSIONS: Cyclic enteral feeding after PPPD is associated with a shorter period of enteral nutrition, a faster return to a normal diet, and a shorter hospital stay. Continuously high CCK levels could be a cause of prolonged time until normal diet is tolerated in patients on continuous enteral nutrition. Cyclic enteral nutrition is therefore the feeding regimen of choice in patients after PPPD.